Automatic coal stoking device



' pri 27, 1937.,` L. H. sEGAR AUTOMATIC COAL STOKING DEVICE Filed Aug. 9, 1934 Z 33 a7 38 4l Q 'i't'ggi "3 INVENTOR BY 77 a ATTORNEYS.

automatic coal stoking device embodying a minivParental Apr'. 27, 1937 UNITED STATES 'PATENT OFFICE AUTOMATIC com. s'roxmG nsvron mma n'. sem, Renton, wash. Application August 9, 1934, erial No. 739,1 54

4 claims. w1. 11o-10s) This invention relates in general to furnace devices. and more particularly has reference to an automatic coal stoker, particularly adaptable to household installations.

While automatic coal stoking devices have been provided for household use previous to this time, they have generally been complex in assembly and expensive of construction. Also the 'mechanisms havev usually been liable to clogging with coal and have burned fuel ineflectively. 'There has in addition often been a back tracking ofv gases rendering the machines objectionable.

The devices used in the past have for the most part required valterations or actual changes in conventional furnace constructions. This has, of course, rendered the use of automatic stokers almost prohibitive in small installations and exceedingly expensive where otherwise suitable furnace equipment has been available.

An object of this invention is to provide an mum of/parts and simple in operation.. Y

Another object of this invention is to provide an automaticv coal stoking device adaptable to an automatic staking device embodying a conveying trough, also forming a grate.

A still lfurther object of this invention is to provide an automatic staking device having a step grate for breaking up the fuel and allowing for the introduction ofv air to promote combustion.

A still further object of this invention is to' provide an automaticcoal stoking'device includ ing an adjustable ,feeding mechanism;

With these and other objects in'view, which may be incident to my improvements,` the invention consists in the parts and combinations to be hereinafter. set forth and claimed,"with the understanding that the several necessary elements comprisinfgmy invention may bel varied in construction, proportions and arrangement, without fuel at a uniform depth for even burndeparting from the spirit and scope of the lappended claims.

In order to make my invention more clearly understood, I have shown in the accompanying drawing means for carrying the same into prac- 'tical eiect without limiting the improvements in their useful applications to the particular constructionawhich, for the purpose of explanation, have been made the subject of illustration.

In the drawing forming part of the specincation: f

, Fig. 1 is a longitudinal section view of my novel automatic, coal stoking device, shown installed 'in a conventional furnace.

Fig. 2 is a 'sectional view taken on line 2-2 of Fig. i.

Fig. 3 is a side view partly in section, showing `my adjustable feeding mechanism.

Fig. 4 is a sectional view taken' on line 4 6 of of Fig. 2.

Fig, 5 is a sectional view taken on line 5 5 of Fig. 2.

Referring more particularly by numerals to the drawing in which the same and similar elements are designated by like symbols oi' reference lthroughout, and more especially to Fig. 1, there is shown my novel automatic coal stoking device in conjunction with a conventional household fur nace installation. I

- It will be seen that my automatic stoker comprises a hopper, I, open at the top for receiving coal indicated by the numeral 2. The hopper is mounted at the outer end of a steel stoker body casing,v3, comprising va bottom and sidewallad and 5, as shown in Fig. 4, and opens therein, as shown by the numeral 6 in Fig. 2.

The coal, 2, is adaptedto feed through the hopper into a cast-iron trough, 1, mounted in the casing, 3, as shown in Fig. 4. The trough, l, is formedwith side walls,l 8 and 9, and angle pieces, i9 and ii, are secured thereto along the rim by bolts, i2. K

The angle pieces are adapted to slide on inwardly extending flanges, l'and il, formed on the rims of the sidewalls, l and 5,'on the casing, 3, as is also shownin Fig. 4. The casing, 3, is provided with a top closure, I 5, having downwardly extending sides, I6 and I1, secured to the sides, and 5, of the casing, 3, by bolts, yi 8.

The trough, 1, for receiving the coal, 2, is adapted to reciprocate longitudinally in the casing, 3, the angle pieces, I0 and I l, secured thereon,

v sliding on the bearing slide rails formed by the flanges, I8 and I4, on the rims of the sides, l

and 5, of the stoker body casing,"3.

An open top cast-iron casing, l, is attached to the front end of the. stoker body casing, 3, by bolts, 2B. A series of spaced step grate bars, 2L angularly arranged with'respect to the horizontal are fixed to the end of the conveyor trough, by mounting between downwardly extending sides, 22, formed thereon. The rst grate bar is spaced twice the distance from the bottom of the troughl l that the succeeding grate bars are spaced from each other.

The rear end of the stoker body casing' 3, extends in a housing, 23, comprising top, bottom v and side portions, for enclosing a driving mechanism. A stationary steel back stay, 2li, for iitj ting in the rear of the conveyor trough,'i, is iixed to the housing, 23, and braced against a gearA box, 25, mounted inthe housing, by a bracket, 2t. The back stay is steel welded and the top forms a saddle for mounting the hopper. The bottoni of the stay, 2d, is formed with a scraper edge composed of stainless steel for working on a wearing plate, 2l, of the saine material bolted `in 'the conveyor trough. The stay and wearing plate' have a valve-like action which provides for relative movement indeiinitely without coal leaking past.'

' The back stay, hbeing stationary, coal fed into the reciprocating conveyor trough from the hopper will contact therewith` and move forward relative to the trough on each outward stroke of the trough; On the inward stroke of the troughA additional coal from the hopper Will be fed` therein.

v'lhe driving mechanism enclosed in the housing, 23, comprises a driving shaft, 2S, extending through a journal, 2Q, and iitted in an end journal, 3u, as shown in Fig. 2. A worm gear, Si,

is keyed on the shaft for engaging a gear, 32.

The gears, 3i and 32, are enclosed inthe gear box, 25, in the housing,23. The gear, 32, is adapted to drive a crank arm formed by an eccentric, 33, having a pin, 3d, seated thereon.-

'I'he shaft, 2t?, has a pulley, 35, keyed on the end thereor` for driving by a motor, titi, mounted on the rear end of the stoking device, through a iexible driving mechanism, tl. The pulley and ilexible' driving mechanism are enclosed in a further supplemental housing, 3S, attached to one side of the housing, 23.

The motor, tit, is also adapted to drive a cont gaging the pin, 3d, and accommodating ballbearlngs, mi2, and inner and outer races, ,d3 and ad; and a reduced extensiomt, formed on .the other end. The reduced extension, 55, is fitted through a knuckle head, 66, xed on a. pin, El, which is pivoted in a draw bar, du, fixed on the rear end of the conveyor trough. The reduced extension, 45, is formed with a further reduced threaded extension, 69, adapted to receive a washer, Nl, and nut, 5l, for securing the connecting rod in the knuckle, #SL

It will be apparent that the reduced extension, 45, will reciprocate in the knuckle, fit, with a conacvaeeo 55, on the end. The sleeve, 52, thus intended for taking up lost motion is locked in place by the nut, 5d. l

The' eccentric for reciprocating the conveyor trough is mounted on a vertical shaft, 5S, journaled in the gear box, 2, and having the gear, 32, keyed thereon. A spacer, i, is interposed between the underside of the eccentric, 33, and the top of the gear box, 25.

A felt .dei'lector, 53, is mounted in the stoker body casing, 3, around the'conveyor trough, l,

on a support, 59, to act as an air stopand prevent the back tracking of air to the gear box chamber.

The casing, 3, is adapted' to be extended within a furnace through the door or other openingas indicated in Fig. l, and any remaining space around the casing enclosed in any suitable'manner. y

The operation of my invention will be readily understood from the foregoing description.

The conveyor trough, l1,I is adapted to receive coal, 2, adjacent the rear end from the hopper, i. The conveyor troughlis adapted to be reciprocated by the motor, 38, driving the crank arm, B, through the series of reducing gears in the box, 25, and through -the lost-motion connecting rod, lili, in the housing, 23.

The length of the stroke of the .conveyor trough is adapted to be adjusted through manipulation of the sleeve, 52, to lengthen or shorten the travel of the lreduced extension, d5, in the knuckle, t. The stroke of the conveyor is shortened by allowing the full length of the reduced extension, i355, to reciprocate in the knuckle, de, or reversely the stroke lengthened by screwing the sleeve, et,

to take up the play of the reduced extension, iid, in the knuckle. A

The housing, 23, may be provided with a cover to allow access to the adjustable drive mechanisrn.

As the trough is reciprocated, coal from the hopper will fall Vtherein. vand be -nioved inward relative to trough by Contact with the stationary back stay, 2S, on each outward stroke o the trough. The Ahopper and reciprocating trough arrangement insure against clogging, as any enlarged object will remain in position without damage to the apparatus and coal will feed therey around. As the conveyor and repot move together the coal is fed on the grates the same depth as in the conveyor trough due to the top, i5, limiting the depth of coal' therein. This it will be readily perceived overcomes the disadvantage of a stationary firepotwherein 'the coal is piled up at the outlet so as to build up an uneven fuel bed.

The step grate tends to break up the coal as it passes thereon for burning. As the grates are angularly arranged the air directed therethrough from the blower is fed in to the coal at a slight angle off the parallel of'the coal feed. This charges the fuel with air instead of allowing the escape of the gases before combustion, as otherwise would obtain if the air was directed at right angles to the fuel feed. The air on the rst grate as the coal leaves the conveyor is double in volume to that on each succeeding grate. The reason for this is that the pre-heated coal, as it leaves the level of the conveyor, has begun to release volaof the conveyor from the v 30 like. .1

i e Y amano e 10 prevent a loss of air and to directvthe air through thegrates. A slight clearance between the casing and fire pot allows suiiicient air to flow therebetween to preventburning out of the fire pot. A small quantity of air is liberated over the sides stoker body casing, 3, which formsan over-draft into the fire and as- -sists in combustion by spreading the flames over a greater area. Y y

The wearing plate, 21, in the conveyor trough prevents the leakage of coal to the rear and the felt, 58, around the conveyor trough prevents the back tracking of fuel-laden air. In addition to the foregoing, a thermostat may be provided in commotion with the blower to vary the quantity of air as the heat in the iire pot varies.

'The stoker body casing may be extended in the. conventional opening in a furnace and any remaining space cemented There is accomplished by this invention automatic coal stoking device particularly adaptv able to household installations, 'embodying a minimum number of parts and simple in assembly, and adaptable to any conventional furnace installation; which -provides for eiiiciently burning fuel-at an even depth without back tracking ofl gases, allowing for the eiiicient introduction vof air to promote combustion and embodying an `40 adjustable feeding mechanism. -s

and described the pre-- While I havel shown ferred embodiment ofmy invention, I wh it to be understood that I do not confine' myself to 'the precise details of constructions herein set forth,

by way of illustration, as it is apparent that changes and variations A by thosev skilled in the art, without departing from the spirit of the invention or exceeding the scope of the appended claims. Y

Iclaim: v

e 1. In combination with a furnace, anautomatlc coal stoking-device comprising a horizontal having one end extending through the furnace wall, a trough mounted 55 in the casing, a stepped grate secured to the inup with fire brick or the? many may' be made therein,-

for sliding movement f direct a current of air Atrough and through the grate.

ner end of the trough and arranged to receivey fuel therefrom, a hopper for delivering coal into the outer end of the trough, means to reciprocate the trough, stationary means adjacent the outer end of the trough for cooperating with the trough to push the coal onto the grate, and means to into the casing under the 2. In combination with a furnace, an automatic coal stoking device comprising a horizontal' casf ing having one end extending through the furnace wall, a trough mounted for sliding move` ment in the casing, a stepped grate secured to Vthe inner end of the trough and arrangedv to receive fuel therefrom, means for delivering coal into the outer end of the trough, a driving mechanism embodying a motor, a series offreduction gear's, a crank arm and a lost motion connecting rod reciprocating the trough in the casing, and

a stationary stay adjacent the outer end of the trough for cooperatingwith the trough to push the coal onto the stepped grate on each outward stroke of the trough. f

3. In combination with a furnace, an automatic coal stoking device comprising a horizontal casing having one end extending through the furnace wall, a trough mounted for sliding movement in the cas a stepped'grate attached to the inner end of the trough and arranged to receive lfuel therefrom, means for delivering coal` into the outer end of the trough, a driving mechanism for reciprocating the trough, stationary means adjacent the outer end of the trough for cooperating with the trough to push the coal onto fhii'rate on each outward stroke of the trough, and means to adjust the length of the stroke of thetrough.

into the outer end of 'rod for varying the length of trough to4 control the quantity of coal pushed on 4. In combination with a furnace, an automatic coal stoking device comprising a horizontal casing having one end extending through the flu'nace wall, a trough mounted for. sliding movement in the casing, a stepped grate attached to Ythe inner end of the'trough and arranged to receive fuelA therefrom, means for delivering coal the' trough, a driving mechvanism for reciprocating the trough, stationary means adjacent the outer end of the trough for cooperating with the trough to push the coal onto the grate on each outward stroke of the trough, and an adjustable lost motion connecting the stroke of the the grate.

LEONARD H. SEGAR. 

